Device for the overdrilling of underground lines

ABSTRACT

A device for overdrilling an underground line includes a rotating push and/or pull linkage having a front end, and a hollow-cylindrical scavenging head which is connected to the front end of the linkage and is equipped with nozzles. At least one of the nozzles has an outlet axis extending at an inclination in a direction of the line in a plane of a longitudinal axis of the scavenging head. In this way, the orifices of such nozzles which optionally also point opposite to the direction of advance are directed onto the line section.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the priority of German Patent Application, Serial No. 10 2005 024 572.2, filed May 25, 2005, pursuant to 35 U.S.C. 119(a)-(d), the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a device for the overdrilling of underground lines, with a rotary-driven push and/or pull linkage, the front end of which is connected to an annular to hollow-cylindrical scavenging head equipped with nozzles.

Nothing in the following discussion of the state of the art is to be construed as an admission of prior art.

Devices of this type serve for exposing underground cables and pipelines (lines hereafter) without excavation and then for renovating them. This takes place in that, with the aid of a scavenging fluid and, if appropriate, with the assistance of cutting and broaching tools, an annular duct surrounding the line is produced, which makes it possible to pull out or press out the old line with a low degree of friction and to pull in or press in a new line.

A device suitable for this purpose is described in DE 195 04 484 C1. This device possesses a linkage, at the front end of which is arranged an annular overdrilling head engaging around the old line and having nozzles for a scavenging fluid which point in the direction of advance. The wall of the annular overdrilling head possesses, approximately by half, an approximately sickle-shaped cross section, on which the linkage running laterally next to the old line engages. The scavenging fluid arrives via the linkage at the nozzles which are arranged in the form of a ring in an irregular distribution and the longitudinal or jet axes of which run parallel to the longitudinal axis of the overdrilling head. Insofar as the nature of the ground allows, the nozzle jets scavenge the line free and at the same time produce an annular duct which is intended to allow low-friction line exchange. However, this is often achieved only incompletely, because the fluid jets of the nozzles arranged in the form of a ring at a distance from the old line cannot reach the line surface, at least not to the extent and with the intensity required for the removal of encrustations, because their axes run parallel to the longitudinal axis of the line or of the overdrilling head.

This is also the case in a device known from DE 100 65 523 C1because the nozzles are arranged in the same way in the form of a ring in the overdrilling or scavenging head. In this device, admittedly, a nozzle ring connected to a rotary drive is equipped with cutting tools for releasing relatively hard soil constituents. However, the tools naturally do not reach the line surface; they would otherwise even damage the line mechanically.

In a further device for the exposure of underground lines which is known from DE 102 11 833 B4, in addition to the overdrilling head, the linkage tip is also provided with a rotary-driven tool which, however, serves essentially only for cutting free for the linkage a duct which laterally accompanies the annular space. This device is intended to avoid free scavenging and therefore operates purely mechanically.

It would therefore be desirable and advantageous to provide an improved device for the overdrilling of underground lines to obviate prior art shortcomings and to provide in the exposure of an underground line without excavation, not only the customary annular space, but at the same time also to free the surface of the line from accretions.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a device for overdrilling an underground line includes a rotating push and/or pull linkage having a front end, a hollow-cylindrical scavenging head connected to the front end of the linkage and equipped with nozzles, wherein at least one of the nozzles has an outlet axis extending at an inclination in a direction of the line in a plane of a longitudinal axis of the scavenging head.

The present invention resolves prior art problems by providing a scavenging head which on the end face possesses at least one nozzle inclined in the direction of the line. The jets from the respective nozzles accordingly impinge onto the line surface and scrape off accretions located there, while other nozzles can be directed in the conventional way parallel to the scavenging head axis or line axis. The cutting head may be provided not only with inclined nozzles arranged on the end face of the scavenging head, but also with nozzles which point in the opposite direction and are inclined at least partially in the direction of the old line and which not only continue to clean the old line, but also improve the discharge of the released earth by means of the scavenging fluid.

So that the device can be operated with different or differently inclined nozzles according to the situation, the device may have a nozzle ring arranged in a scavenging head carrier. In this way, nozzle rings equipped very differently with nozzles and/or tools can be used on the nozzle carrier by simple exchange or worn nozzle rings can be replaced.

Moreover, the nozzle ring may be mounted rotatably and be connected to a rotary drive which preferably possesses two directions of action. Preferably, however, the linkage is connected to a rotary drive which possesses two directions of action and thus allows a rotating to-and-fro movement, so that each nozzle is moved on a part circle.

In order also to provide in the earth a free space required for the advance of the linkage, the front end of the linkage and/or the scavenging head carrier may be additionally equipped with nozzles.

A particularly stable structure is obtained when the front end of the linkage engages into an approximately U-shaped recess in the casing of a hollow-cylindrical scavenging head carrier which likewise engages around the old line. The casing of the scavenging head carrier in this case engages around the appliance tip in an approximately horseshoe-shaped manner.

BRIEF DESCRIPTION OF THE DRAWING

Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:

FIG. 1 is a perspective view of a front part of a linkage with a scavenging head according to the present invention;

FIG. 2 is a front view of FIG. 1, taken along a section perpendicular to a longitudinal axes of the linkage and line;

FIG. 3 is a perspective illustration of a nozzle ring; and

FIG. 4 is a perspective illustration of the linkage with a scavenging head carrier without a scavenging head and old line.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.

Turning now to the drawing, and in particular to FIG. 1, there is shown a device according to the invention which essentially includes a linkage 1 which is provided with a rotary-driven push and/or pull drive, not illustrated, and of which only the front part is illustrated.

The linkage 1 engages with its front end into an approximately U-shaped recess 2 in the casing 3 of a scavenging head carrier 4 which engages around an old line 5 extending approximately parallel to the linkage 1 and the rear end of which is beveled. The bevel 14 reduces the amount of friction between the line 5 and the casing of the scavenging head 4 and the risk of blockages in the annular space between the old line 5 and the scavenging head casing to a minimum. The linkage tip 6 is provided with a nozzle 7 and laterally adjoins the scavenging head casing which at the same time engages with its U-shaped recess 2 around the front part of the linkage 1 in an approximately horseshoe-shaped manner. This results in an extremely stable, in particular flexion-resistant connection between the scavenging head carrier 4 and the linkage 1 or the linkage tip 6.

The scavenging head carrier 4 serves for receiving a nozzle ring 8 which is rounded on the end face to avoid line damage and which is provided with cutting and broaching tools 9 and nozzles 10, 12 and a plurality of nozzles 11 pointing in the opposite direction. It may be arranged rotatably on the nozzle carrier 8 and be connected to a specific rotary drive, not illustrated. The outlet direction of the nozzle group 10 runs parallel to the longitudinal axes of the old line 5 and of the nozzle ring 8, while the nozzles in the nozzle groups 11, 12 are inclined such that the emerging jets impinge at least for a substantial part onto the line 5.

The cutting and broaching tools 9 for cutting free more stable or harder earth constituents are arranged in each case between the front-side nozzles 10, 12.

The nozzles 10, 11, 12, encircling the old line 5 over a part-circular arc as a result of the rotating pendulum movement of the linkage, not only produce the necessary free space for pulling out or pressing out the old line 5, but also largely expose the line surface, so that a low-friction removal of the old line from the earth is possible. Moreover, the nozzle 7 in the linkage tip 6 ensures a low-friction advance of the linkage during the exposure of the old line and during a return movement of the linkage when a line section running between a starting excavation and a target excavation is exposed and the linkage is then pulled back into the starting excavation. The linkage or the scavenging head carrier may in this case be connected to an exchange line.

While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and includes equivalents of the elements recited therein: 

1. A device for overdrilling an underground line, comprising: a rotating push and/or pull linkage having a front end; and a hollow-cylindrical scavenging head connected to the front end of the linkage and equipped with nozzles, wherein at least one of the nozzles has an outlet axis extending at an inclination in a direction of the line in a plane of a longitudinal axis of the scavenging head.
 2. The device of claim 1, wherein the outlet axis for the at least one nozzle extends in parallel relationship to the longitudinal axis of the scavenging head.
 3. The device of claim 1, wherein a first plurality of the nozzles points in a feed direction, and a second plurality of nozzles points in an opposite direction.
 4. The device of claim 1, further comprising a scavenging head carrier and a nozzle ring which connects to the scavenging head carrier and at least partly accommodates the nozzles.
 5. The device of claim 4, further comprising a rotary drive connected to the nozzle ring.
 6. The device of claim 5, wherein the rotary drive operates in two directions of action.
 7. The device of claim 4, wherein the nozzle ring is equipped with cutting and/or broaching tools.
 8. The device of claim 4, wherein the nozzle ring has a rounded end face.
 9. The device of claim 1, wherein the linkage has a tip provided with at least one nozzle.
 10. The device of claim 4, wherein the scavenging head carrier is provided with at least one nozzle.
 11. The device of claim 1, wherein the scavenging head carrier has a casing formed with a recess, said front end of the linkage being arranged in the recess of the casing.
 12. The device of claim 1, wherein the scavenging head carrier has a beveled rear side.
 13. The use of a nozzle ring of claim 4 for equipping a scavenging head carrier. 